Print a Doubly Linked List in Reverse - c++

Question

I have a list that is dynamically created based off of user input. I can add strings, and I can remove strings, but I am at a loss on how to properly print this in reverse.
Example:
input : First Second Last
output: Last Second First
I have tried a few things, and I have looked up what needs to be done, but I am having a tough time getting it correct.
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
// define a node for storage and linking
class node{
public:
string name;
node *next;
node *prev;
};
class linkedList{
public:
linkedList() :top(NULL){}
bool empty(){ return top == NULL; }
node *getTop(){ return top; }
void setTop(node *n){ top = n; }
void add(string);
int menu();
void remove(string);
~linkedList();
void reversePrint();
friend ostream& operator << (ostream&, const linkedList&); // default
output is in-order print.
private:
node *top;
node *end;
};
void main(){
linkedList l;
cout << l.empty() << endl;
int option = 0;
string s;
bool go = true;
while (go){
option = l.menu();
switch (option){
case 1: cout << "enter a name: "; cin >> s; l.add(s); break;
case 2: cout << "enter name to be deleted: "; cin >> s; l.remove(s); break;
case 3: cout << l; break;
case 4: cout << l.reversePrint(); break; // I am getting a Syntax error here
case 5: cout << "exiting" << endl; go = false; break;
}
}
system("PAUSE");
// l goes out of scope and calls ~linkedList()
}
void linkedList::reversePrint()
{
node *start_ptr = NULL;
node *current = start_ptr;
node *prev = NULL;
node *next = NULL;
while (current){
next = current->next;
current->next = prev;
current->prev = next;
prev = current;
current = next;
}
}

Answer 1

You didn't provide complete code (such as the implementation of linkedList::add()) so it's hard to give the correct answer...
According to your partial code, since the return type of reversePrint() is void, you can not cout it.
Therefore, in the switch block in main function should be:
case 4: l.reversePrint(); break;
I try to modify your code but not sure if it's correct since I don't have the code.
void linkedList::reversePrint()
{
node *current = end;
while (current){
cout << current->name << " ";
current = current->prev;
}
}